Musicians and social movements have often made congenial bedfellows. In the ‘60s, the SNCC Freedom Singers empowered the African-American civil rights cause with rousing spirituals and folk songs. Occupy Wall Street’s call to take up for those who’ve suffered for someone else’s greed has been inspiring message songs for the past year. And the Farm Aid festival is still supporting struggling family farmers over a quarter century after Willie Nelson, Neil Young and John Mellencamp founded the event.

The Half the Sky movement started with a book that told very real stories of women in the developing world who are oppressed simply because they’re women — some, for example, forced into prostitution and others physically tortured — and it’s now expanded into a documentary and an awareness-raising online project called 30 Songs/30 Days. Every day in September, you can download a track by a different female artist who’s lent her music to the cause.

The performers hail from far flung corners of the musical landscape. Among them are the sorts of mainstream pop and rock acts who’ve played Lilith Fair, like Joan Osborne and Sheryl Crow, R&B performers who nod to African roots (from a teamed-up Angelique Kidjo and Alicia Keys to Malian star Oumou Sangare) and intelligent indie rock singer-songwriters, including Feist.

Go down the list, and you’ll also find a good many musicians with Americana leanings. There’s Lucinda Williams, Brandi Carlile, Patty Griffin and the McCrary sisters, whose cover of Bob Dylan’s folkie protest classic “Blowin’ in the Wind” hearkens back to the days when Regina McCrary sang in Dylan’s backing band. Then there are rootsy performers who are recognized for their consistent involvement with worthy causes, like Bonnie Raitt, Emmylou Harris and old-time banjo-playing singer-songwriter Abigail Washburn.

Washburn is the perfect candidate for addressing an international need. She knows traditional American folk music inside and out, but for as long as she’s been playing the clawhammer banjo, she’s also used it as a means of global engagement.

At one point, Washburn had her heart set on pursuing a law degree in China. Instead, she fell into a music career. But she’s racked up plenty of frequent flyer miles making trips back and forth to mainland China to share old Appalachian folk tunes and new songs while and learning the Chinese folk repertoire from conservatory-trained virtuosos, taxicab drivers and all sorts of unexpected collaborators. It’s safe to say she’s the only Americana act who writes lyrics in both English and Mandarin.

For Washburn, building cultural bridges, shaping perspectives, provoking thought and generally doing good in the world fits right alongside expressing herself and entertaining audiences. After China’s Sichuan province was ravaged by an earthquake, she traveled to the region with a Chinese-American producer, made field recordings of school children whose lives had been upended by the natural disaster and put out an electro-folk benefit album called Afterquaketo benefit Sichuan residents.

The song Washburn selected for 30 Songs/30 Days is the title track of her 2011 album, City of Refuge. It kicks off with a circling banjo figure, and she soon begins to sing, in graceful, elongated phrases, the story of a young American woman who recognizes how comfortable her middle-class life is and itches to escape her limited experience of the world so that she can feel connected to something bigger than herself.

From another angle, you might say “City of Refuge” is a song about fostering empathy for people who live very different lives. That puts it perfectly in step with Half the Sky’s efforts to make known what women from Pakistan to Tanzania to Cambodia are going through every day and to free them from radical injustice.